RF Setup

[7uptruckracer]

I was out of the game most of last year and have gotten behind. I focused on my asphalt stuff. What’s the current trend of RF. Was running a 225 with a red Penske cone bump but struggled for mid corner sidebite and drive off. Lowering RRL bar didn’t help. Lowering Jbar on Pinion didn’t help. Raising RR spring rate didn’t help and taking 2-4 turns out RR didn’t help, taking LF chain tie down didn’t help. I’m thinking something with the RF just didn’t agree but can’t figure out if it was just on the RF to long and couldn’t get the correct transfer to the rear or what it is. I want to try a RF stack but I have no clue what they run these days or how much they engage them. Do you still want the same dynamic load and do you want the same engagement window as I had with the bump?

[grt74]

most are working in a 1 to 1 1/2 inch window on the rf now, don't forget to think about the rr, people are working really hard there too
the problem is,most of this fine fine tuning is very track dependent, so ,and i can not stress this enough,KEEP GOOD NOTES, that is going to win races
load at certain numbers are everything these days, no one cares about ride heights anymore (of coarse this is after the car is scaled a checked for alignment) only to pass tech heights at the beginning on the race, the only reason we run all this crazy chit is to pass tech, then its all about dynamic load and tire patch, start thinking that way and i think you'll see a whole different picture
just trying to get you thinking here, not being a wise guy here at all
kind of car will help
make sure your checking your rf load numbers everyweek on a smasher, if your not, depending on your bumps, i think you'll find out things change from week to week

[7uptruckracer]

I purposely left out the chassis type, I have all my static and dynamic load numbers. Car is awesome early in the night. Once it blows off though the car doesn’t respond to any changes. You can do all the stuff mentioned and it acts the same way. I don’t know if I don’t have enough RF load or I’m tied down to much on the RF I’m not sure how you tell. It’s just like the RR won’t catch the car and by mid turn it’s over rotated and you either can’t gas it up without spinning or it does straight the car when you gas it but you are cooking the RR if that makes sense, now with ALL that being said I have yet to rule out the driver as the problem


most are working in a 1 to 1 1/2 inch window on the rf now, don't forget to think about the rr, people are working really hard there too
the problem is,most of this fine fine tuning is very track dependent, so ,and i can not stress this enough,KEEP GOOD NOTES, that is going to win races
load at certain numbers are everything these days, no one cares about ride heights anymore (of coarse this is after the car is scaled a checked for alignment) only to pass tech heights at the beginning on the race, the only reason we run all this crazy chit is to pass tech, then its all about dynamic load and tire patch, start thinking that way and i think you'll see a whole different picture
just trying to get you thinking here, not being a wise guy here at all
kind of car will help
make sure your checking your rf load numbers everyweek on a smasher, if your not, depending on your bumps, i think you'll find out things change from week to week

[drgracer392]

RF load or tied down too much would be my guess.... I gonna say if it turns well with the soft RF but don't have drive its a RF load issue say its too soft.

[7uptruckracer]

Maybe this will load it’s a load photo on RF 225 with a Blue like rubber and 225 without blue line rubber


RF load or tied down too much would be my guess.... I gonna say if it turns well with the soft RF but don't have drive its a RF load issue say its too soft.

[fastford]

the problem with drive off on a soft rt frt and bump or two stage either one is usually in the left rear , it took me a while to get my head wrapped around it , but in the end , left rear bar angle and drop was where most of my problems were fixed , dynamic rear steer is critical,,,,,JMO,,,,

[ZERO25]

Im assuming you mean loose off the gas. I would try more lf spring and less lr bite. I know a guy who wins regularly in a bwrc, his lr bite is wayyyyyy low!

[MasterSbilt_Racer]

the problem with drive off on a soft rt frt and bump or two stage either one is usually in the left rear , it took me a while to get my head wrapped around it , but in the end , left rear bar angle and drop was where most of my problems were fixed , dynamic rear steer is critical,,,,,JMO,,,,
I agree. But I've found vastly different numbers work at different type tracks.

[MachineMasters]

To me it sounds like the RF is locked down too hard with rebound.. I would open up the adjuster a few clicks and see if it doesn't get better.

Keep in mind it will tighten the car through the center..so if the root cause of your issue now is the car being overly tight, taking RF rebound out would likely make the problem worse.

[7uptruckracer]

So I’ve been doing some digging. My 3” number is around 1400# 3.5” is about 1600# 4” about 1800#
4.5” is about 2200# and 4.75 is 2700#. Now should I be lowering rate as the track slicks off to keep posture or should I be adding shim to ramp it up so it can push back on the LR? What would you think of you saw these numbers? This is on a 225 with a rubber and a red Penske bump but I’m not sure I like the Penske bump. I really think a stack might be better. Currently only going to one track with this car

[MasterSbilt_Racer]

Even with my moderized Gen X, I can't travel that far. That's my first observation.

In a perfect world, your travel wouldn't change. Nor would the loading bias (front to rear) with lateral weight transfer, if your car was balanced correctly.

[JustAddDirt]

Sounds like an xr1 with those travel Numbers

[7uptruckracer]

Shocks installed height is 18.25 pin to pin and this number is down to 13.5. On a Ohlins LMP they said can go to 12.8. It’s a lazer they said it can travel 5” and they said to make sure it stops there, which would be be a 13.25 center to center. I need to take it out to double check but I know we do travel it to the 13.5 when the tracks hammer down this is a 358 steel head wet sump division


Even with my moderized Gen X, I can't travel that far. That's my first observation.

In a perfect world, your travel wouldn't change. Nor would the loading bias (front to rear) with lateral weight transfer, if your car was balanced correctly.

[Mr.Kennedy777]

One thing that could be affecting your side bite mid turn is also your drop load. Too much drop load in LR can hurt your side bite I've found. Steer and thrust play a role too but I'd be looking at the drop load numbers.

[7uptruckracer]

200# extension load


One thing that could be affecting your side bite mid turn is also your drop load. Too much drop load in LR can hurt your side bite I've found. Steer and thrust play a role too but I'd be looking at the drop load numbers.

[PushinTheLimit]

Mr. Kennedy777... can you explain what you mean in more detail on drop load in the LR? I've been struggling to find traction when the tracks slick off late in the night and feel like my car is more on top of the track than in it. Just no side bite in mid corner and no forward bite on exit.

[MasterSbilt_Racer]

Mr. Kennedy777... can you explain what you mean in more detail on drop load in the LR? I've been struggling to find traction when the tracks slick off late in the night and feel like my car is more on top of the track than in it. Just no side bite in mid corner and no forward bite on exit.

Load remaining in spring at full hike.

[Jking24]

I don't know where your racing but with those numbers your not traveling anywhere near 4+inches late on the night if it's not crashing there nose early

[MasterSbilt_Racer]

I don't know where your racing but with those numbers your not traveling anywhere near 4+inches late on the night if it's not crashing there nose early

That going to depend a lot on moment arms. Maybe not on your car, but I would be.

[Jking24]

That going to depend a lot on moment arms. Maybe not on your car, but I would be.Yes i agree masters but i have a little experience with lazer and i don't think their front geometry has changed much since what I've messed with.

[7uptruckracer]

What do you mean crashing the nose early?


I don't know where your racing but with those numbers your not traveling anywhere near 4+inches late on the night if it's not crashing there nose early

[TheJet-09]

^^^ Just guessing, but he probably means early in the night...when there's still traction and greater speeds.

I picked up a used Lazer, so I'm following along.

[Jking24]

Yes i agree masters but i have a little experience with lazer and i don't think their front geometry has changed much since what I've messed with.
What do you mean crashing the nose early?If the valance isn't hitting the race track early in the night Then the car isn't traveling late in the night if your running the same load numbers all night especially with you being a asphalt racer aswell. Your likely a heavy braker by nature also steel block cars tend to travel the rf a little more. If your trying to travel it 5 inches you are way high. With your numbers i would be surprised if you were getting much over 4

[Jking24]

Also if your running in the pa area nobody better to talk to then Jim himself. He's generally very open with his customers

[7uptruckracer]

It will scuff valance in hammer down. The car will travel about 4.5 in the slick and 4.75 in the tacky, I grew up running dirt and lates before I went to asphalt to run mods but still run both, but that being said this is a car I setup and am not driving myself, I spoke with both drew and Jim today at Lazer and they gave me some stuff they are currently doing and some stuff to check. My lines of thinking were in line with them but they provided some more inside on some new LF loads and rr loads they are running and why they are running it and some more stuff in the LF to do to keep it off the RR in certain areas. Some of it was ways to maintain posture as the track slows and some of it was just flat out new loads they are running compared to before. The biggest difference was getting off the 225 RF bump and onto a stack. I was thinking a 175/400 but they suggest something along those lines but still with a bump so it’s not crashing the nose but I still can get to posture sooner, if that makes sense.


If the valance isn't hitting the race track early in the night Then the car isn't traveling late in the night if your running the same load numbers all night especially with you being a asphalt racer aswell. Your likely a heavy braker by nature also steel block cars tend to travel the rf a little more. If your trying to travel it 5 inches you are way high. With your numbers i would be surprised if you were getting much over 4

[Jking24]

I don't know alot about there specifics of Jim's front end but i would still be Leary of the drivers braking habits. You won't know until you watch the valance closely on corner entry especially at the center or just before it between braking and initial throttle pickup. No matter what Jim should be able to help get you going